Assignment 2 Task 3

This project displays an interactive agricultural land use/land cover and watershed distribution map of the Hawaiian Islands. This map can be utilized to determine the composition of agricultural land use and land cover within a specific watershed. This can be useful for hydrological modeling projects in predominantly agricultural regions within Hawaiian watersheds.

1. Load necessary packages.

library(tidyverse)
library(janitor)
library(kableExtra)
library(naniar)
library(skimr)
library(sf)
library(tmap)
library(paletteer)
library(lubridate)
library(here)

2. Read in the data: watersheds and land use/land cover for the Hawaiian Islands

watershed <- read_sf(dsn = here(".", "Watersheds"),
                 layer = "Watersheds") %>% 
              st_transform(crs = 4326) # Set the coordinate reference system 

lulc <- read_sf(dsn = here(".", "Land_Use_Land_Cover_LULC"),
                layer = "Land_Use_Land_Cover_LULC") %>% 
              st_transform(crs = 4326) %>% 
  filter(landcover == "Cropland and Pasture" |
           landcover == "Shrub and Brush Rangeland" |
           landcover == "Orchards, Groves, Vineyards, Nurseries and Ornamental Horticultural Areas" |
           landcover == "Herbaceous Rangeland" |
           landcover == "Mixed Rangeland" |
           landcover == "Other Agricultural Land") # For the purposes of this map, interested in displaying rangeland and agricultural areas, so filtering out other land covers

3. Create an interactive map of the watersheds and land use/land cover for the Hawaiian Islands

hawaii_tmap <- tm_basemap("Esri.WorldImagery") + # Put in a basemap
  tm_shape(watershed) +
  tm_borders("lightblue", lwd = .5) +
  tm_shape(lulc) +
  tm_fill("landcover", 
          title = "Land Cover", 
          palette = c("orange", "purple", "blue", "yellow"), 
          alpha = 0.5) +
  tm_layout("Agricultural Land Use/Land Cover for Watersheds of the Hawaiian Islands") +
  tm_view(view.legend.position = c("left", "bottom"))

tmap_mode("view") # Sets it to interactive view

hawaii_tmap

Figure 1. Agricultural land use/land cover and watershed distribution of the Hawaiian Islands. Data source: Hawaiian Statewide GIS Program.